An algorithm for stabilizing unstable steady states for jacketed nonisothermal continually stirred tank reactors

The operation of nonisothermal jacketed continually stirred tank reactors (CSTRs) involves a high degree of nonlinearity, and for certain operating conditions this nonlinearity may cause concentration multiplicity at steady state. At these conditions, certain steady states will be unstable and difficult to observe and maintain. The dynamics of the cooling jacket has a profound effect on these conditions and hence should be taken into consideration for the proper reactor design. A novel steady-state design algorithm is presented here to stabilize the CSTR at such conditions. This is achieved by replacing the single CSTR by a cascade of reactors that are capable of stabilizing and maintaining the unstable steady state. The new design approach implements an optimization of the reactors operating parameters to achieve this solution. The implementation of the solution algorithm is shown graphically and also shown is the use of numerical computational optimization solution techniques. For a first order reaction, both solutions were successful at achieving the unstable steady state; however, the numerical solution was more accurate. Simulations of the new design showed that the reactors' cascades were capable of stabilizing the metastable temperature to a high degree of accuracy.